Invasive alien species of Union concern remain present in all EU Member States, with hotspots in densely populated areas, along rivers and near major transport hubs, according to a briefing published by the European Environment Agency (EEA) on 29 June 2026. The briefing, titled 'Recent progress in managing invasive alien species in the EU', covers the 2019-2024 reporting period and summarises national implementation of the EU Invasive Alien Species Regulation 1143/2014. It notes that more than 300 rapid eradication response actions resulted in almost 200 successful eradications, and over 4,200 management measures were implemented, more than half of which successfully mitigated negative impacts on biodiversity. However, the EEA warns that increased efforts are required as invasive alien species continue to spread and new species are likely to be introduced.
The briefing is based on reports from all 27 Member States on 87 species of Union concern (88 listed, but one excluded as it takes effect from 2027). The most widespread species include the pond slider (Trachemys scripta), reported by 26 Member States, and the tree-of-heaven (Ailanthus altissima), reported by 24. A total of 69 species have become established in the environment, with three — Himalayan balsam, pumpkinseed and signal crayfish — established in more than 20 Member States. The EEA highlights that 68 species (78%) were introduced before 2019, and natural dispersal from neighbouring Member States was the pathway for over 30% of introductions. Maps show continued spread of species such as the Egyptian goose, northern raccoon, common milkweed, Nuttall's waterweed, Chinese mitten crab and Asian hornet.
Rapid eradication efforts increased compared to the previous reporting period: 23 Member States undertook over 300 actions, with 60% fully, partially or temporarily successful, while only 15% had no effect. Management measures, undertaken by 25 Member States, totalled over 4,200 actions, with 33% resulting in complete, partial or temporary eradication, 8% in containment and 8% in control. However, for 44% of measures the outcome is still pending. The briefing also notes that 19 Member States issued permits for 70 species, mainly for research or ex situ conservation, but discrepancies between authorised and actual specimen numbers highlight the need for more rigorous inspections. All Member States have prioritised pathways of introduction, with 'Escape from confinement' being the most common category. Additionally, 13 Member States have established national lists of invasive alien species of concern, covering species not listed at EU level, such as the zebra mussel and brown bullhead.
The EEA concludes that while significant progress has been made, particularly in early warning and rapid response, increasing efforts are needed to reduce the spread and negative impacts of widespread invasive alien species. The briefing serves as a six-yearly assessment under the IAS Regulation and underscores the ongoing challenge of managing biological invasions across the EU.